The present invention relates generally to telecommunications systems, and relates more specifically to a device and system for providing wireless backup telephone service for landline telephone equipment.
Telephone service in the North America is one of the most reliable communications systems in the world. The public switched telephone network (PSTN), or landline network, uses copper and fiber optic land-based telephone lines as the standard for connecting end-user telephone equipment to the network. Landline telephone equipment, known in the art as customer premises equipment (CPE), receives and sends telephone calls through the landline network. The reliability of the landline network creates a consumer expectation of trouble-free, uninterrupted telephone service. Nevertheless, landline telephone service occasionally becomes interrupted, primarily due to damage caused to overhead landlines during severe weather.
For example, landline telephone service often becomes interrupted during extreme weather events, such as hurricanes, floods, and ice storms. Because these weather events often coincide with electric power outages and very difficult traveling conditions, many subscribers, such as the elderly, immobile persons, persons caring for young children, and persons relying on home-based medical equipment may find that these extreme weather events are the most important occasions to have telephone service available. Emergency response personnel, private contractors specializing in tree removal, insurance adjusters, government officials, and utility personnel may also have an increased need to maintain telephone service during extreme weather events. Though no system can be guaranteed 100 percent reliable, these and other subscribers may be willing to pay for any gain or increase in reliability of their telephone service.
In addition, when landline telephone service becomes interrupted, a delay in the repair time may occur if the service provider is not notified as soon as possible. In some cases, the consumer may not realize that his or her telephone service has been interrupted for an extended period, and the service provider will not be able to react until the consumer notifies the service provider of the interruption. For example, if a subscriber""s home telephone service becomes interrupted while the subscriber is at work, the subscriber might not learn of the interruption until returning home from work several hours later.
Moreover, the telephone network is often relied on for security systems, such as burglar alarms, fire alarms, home-based medical monitoring systems, home-arrest prisoner monitoring systems, and the like. In other words, the current landline telephone system serves as the communication infrastructure for a large part of the remote monitoring and security systems for businesses and homes by police, fire, emergency medical personnel, and private security providers. For instance, many homeowners use burglar alarms programmed to call the police or an alarm monitoring company when the alarm is triggered. These burglar alarms, in turn, use the landline telephone system to communicate the alarm notifications to the proper authorities. As a result, intentionally cutting the landline providing telephone service to the home defeats the notification feature of the alarm system.
One approach for solving the problems described above would be to issue a conventional wireless telephone to each landline subscriber. However, this approach would allow each subscriber to use both the landline equipment and the wireless telephone at the same time. This type of increase in telephone service typically involves a monthly service charge that many subscribers may be unwilling to pay. In addition, assigning a second wireless directory number for each existing landline directory number would consume a large number of directory numbers, which could deplete the number of available directory numbers in some areas. Alternatively, upgrading the telecommunications infrastructure to allow wireless telephones to use the same directory numbers as landline telephones on a large scale basis would require a significant investment in the existing telecommunications infrastructure.
Thus, there is a need for devices to increase the reliability of landline telephone service. In particular, there is a need for a device capable of backing up landline customer premises equipment during landline telephone service interruptions. There is a further need for a technically and economically feasible mechanism for backing up landline telephone service without unnecessarily depleting the supply of directory numbers or significantly increasing the existing telecommunications infrastructure.
The present invention solves the problems described above in a wireless backup device that provides emergency backup telephone service to landline telephone equipment. This backup device detects interruptions in landline telephone service and automatically provides backup telephone service to the landline telephone equipment through a wireless telephone. The backup device also notifies the telephone service provider that the landline service has been interrupted, and may also notify the homeowner that telephone service has been interrupted, for example through an indicator on an alarm panel. Because the backup device uses wireless communications, it provides backup service even when the landline system is suffering widespread outages, such as during extreme weather events. The backup device also increases the reliability of security and monitoring systems by providing an alternate communication system in cases of intentional landline telephone service interruptions.
In addition, because the backup device operates only during very infrequent landline service outages, a large number of backup devices can be supported by a relatively small number of temporary directory numbers. That is, because a particular temporary directory number can be assigned to a backup device only while that device is in operation, and then reassigned to another backup device at a later time, a large number of backup devices can be installed without severely burdening the supply of directory numbers. Similarly, because each backup device operates very infrequently, a telephone service provider can support a large number of backup devices without significantly increasing the existing telecommunications infrastructure.
The backup device also provides an additional service that telephone service providers can offer as a value-added service to their subscribers. This may be a particularly important advantage in an environment of increased competition among telephone service providers. Because this type of backup service can be implemented without depleting the supply of directory numbers or significantly increasing the existing telecommunications infrastructure, it can be offered to subscribers at a relatively low cost. For example, it is expected that this type of backup service will be offered at a fraction of the cost of full-time wireless telephone service.
Generally described, the invention is a device and system for backing up landline telephone service to customer premises equipment. The backup device detects interruptions in the landline service connection and, in response, powers on a wireless communication device. An interconnection circuit then functionally connects the customer premises equipment to receive telephone service through the wireless device. The interconnection circuit also supplies traditional landline service features to the customer premises equipment, such as dial tone and ring voltage. Once switched into connection with the customer-side of the landline, the backup device provides what appears to be normal landline voice telephone service to all of the customer premises telephone equipment. Specifically, the backup device provides all of the customer premises equipment with ring voltage for incoming telephone calls, and dial tone with normal dialing for outgoing telephone calls.
To enable incoming as well as outgoing telephone calls, the backup device automatically forwards the landline telephone service to a temporary directory number assigned to the wireless device in the backup device. Specifically, the wireless device communicates through radio channels with a mobile telephone switching office (MTSO) of a wireless communication network. Upon powering on, the wireless device automatically registers with the MTSO, obtains a temporary directory number from the MTSO, and transmits a forwarding message to forward telephone calls directed to the landline directory number to the temporary directory number. This forwarding message is then relayed to a telephone redirection device, such as a switch servicing the landline or a local number portability platform (LNPP), to implement call forwarding for the landline telephone service.
More specifically, bi-directional backup telephone service for the customer premises equipment is enabled as follows. For outgoing telephone calls, someone in the premises dials a desired directory number from the customer premises equipment. The interconnection circuit transfers the directory number from the customer premises equipment to the wireless communication device, which sends a call origination message containing the dialed directory number to the wireless network. The wireless network, in some cases in combination with the landline telephone system, then connects the outgoing telephone call to the customer premises equipment by way of the wireless device.
For incoming telephone calls, a calling party dials the subscriber""s landline directory number. Somewhere in the routing of the telephone call to the landline, a telephone redirection device forwards the telephone call to the temporary directory number assigned to wireless unit in the backup device. This call forwarding feature routes the telephone call to the MTSO where the wireless unit of the backup device is registered. The MTSO then connects the telephone call to the customer premises equipment by way of the wireless device. The telephone redirection device may typically be the switch that services the landline for the customer premises equipment. Alternatively, the telephone redirection device may be an LNPP that is typically consulted by the originating service switching point (SSP) for the incoming telephone call.
The backup device also detects resumption of telephone service provided by the landline to the customer premises equipment. The interconnection circuit then disconnects the customer premises equipment from the wireless communication device, and powers down the wireless communication device. The backup device may also transmit a message instructing a telephone call redirection device to unforward telephone calls to the directory number assigned to the wireless communication device to the directory number assigned to the customer premises telephone equipment.
The backup device may be incorporated into a premises alarm system, such as a home or business alarm. In this case, the backup device detects landline interruptions to the customer premises equipment, provides backup telephone service as described above, and also provides an indication of the landline interruption through the alarm system, typically by illuminating an indicator on an alarm panel. The alarm system may also implement other types of indications, such as a distinctive dial tone, distinctive ring, announcement, and the like. In addition, the alarm system may notify others of the landline interruption, for example by placing a telephone call or sending an e-mail to the telephone service provider, the police, an alarm monitoring company, the homeowners"" office telephone number, and so forth. Upon reactivation of landline service telephone service, the alarm system deactivates the landline interruption indicator, and may also notify others of the resumption of landline interruption.
Other objects, features, and advantages of the present invention will become apparent upon reading the following specification, when taken in conjunction with the drawings and the appended claims.